"Hunter Killer" is the third campaign mission of Call of Duty: Modern Warfare 3. The player takes on the role of Sgt. Derek "Frost" Westbrook, as he and his squad infiltrate a RussianOscar II-class SSGN and launch the boat's cruise missiles against their own fleet to cripple it. Later, the player and other team members make their escape from the submarine on Zodiac watercraft as the launched missiles begin to bombard the Russian ships in the area, before escaping in a CH-46 Sea Knight.

There they rendezvous with a team of SEALs, and continue toward their objective. The depths of the harbor are filled with mines and Frost is instructed to navigate around them using a mine imaging sonar device on the his DPV.

After successfully passing through the minefield, the team then plants charges on an enemy submarine. The charges detonate and the submarine is forced to surface, allowing the team to board. Frost and Sandman enter through the sub's access hatch and fight their way through the submarine and up to the bridge. The two of them breach the bridge, killing all the sailors within and their commanding officer (possibly the captain). From the bridge, Frost and Sandman are able to launch the Russian's missiles against their own fleet.

Frost and Sandman then board a Zodiac watercraft that the SEALs have put in place, and make their escape as the battle for New York Harbor rages around them. They are then extracted by a CH-46 Sea Knight and are flown away from Manhattan.

Once inside the submarine, be on the lookout for a room that includes a few bunk beds. Walk to the last one, then look in the corner for the intel.

On the second floor of the submarine, the intel is in the fuel tank room located just before breaching the missile control room. All of the enemies in this room have laser targeting on their guns so it is hard to miss. Get up on the scaffolding to grab the intel.